MAKING COMPOST FROM GARDEN WASTE Stuart High School Whyalla
Quick Facts... Composting garden and yard waste recycles nutrients back into the yard and saves landfill space. Composting reduces household waste volume by 50 to 75 percent. The microorganisms that break down plant wastes require favorable temperatures, moisture and oxygen. Compost can be used as a soil amendment and mulch. Composting Step by Step Step One: Choose A Compost Bin There are many types of bins used to hold the composting materials. There are commercially made square or cone shaped plastic bins, homemade square bins often made of wood, and rotating tumbler style bins just to name a few. Each type of bin has its' own advantages and disadvantages but all types of bins can be used for composting. Step Two: Select a Location for Your Compost Bin Choose a site that is level and well drained, as well as easily accessible all year round. Place the bin over bare soil rather than concrete or paving to ensure that worms and other beneficial organisms can make their way into the pile. It's a good idea to remove any grass or plants and turn the soil to a depth of about 6-8 inches.
Step Three: Add Good Composting Materials Generally, composting ingredients can be divided into two categories: Brown materials such as leaves, hay, straw and paper and green materials such as grass clippings, fresh manure, vegetable trimmings and most green plant cuttings. Browns leaves hay & straw paper & cardboard woody pruning eggshells tea bags sawdust Greens vegetable peelings fruit peelings grass clippings coffee grounds fresh manure green plant cuttings annual weeds young hedge trimmings
Step Four: What Not To Add to Your Compost! There are a number of materials that you should keep out of your compost pile. Adding some items, like vegetable fats and dairy products will simply slow down the composting process by excluding the oxygen that helpful organisms need to do their job. If you add these materials you will still have usable compost, it will just take much longer. Adding other materials to your pile is simply dangerous because of the chance of poisoning or disease. Human and pet feces, chemically or pressure treated wood or sawdust, and meat and animal fats fall into this category and should never be added to your compost pile. Don't Add meat & bones poultry & fish fatty food waste whole eggs dairy products human & pet faeces pernicious weeds treated wood
Step Five: Making Great Compost Making great compost is like making a giant layer cake! Well, not exactly but you will soon see what I mean. Start with a 4 inch layer of brush, twigs, hay or straw at the bottom of the bin. Then add a 4 inch layer of brown material, then a thin layer of finished compost or good garden soil. That's one layer. Then add a 4 inch layer of green material topped with a thin layer of compost or soil. Moisten each layer by misting it lightly with a garden hose. Keep adding materials in alternating layers of greens and browns until the bin is full. Once you have a full bin you can turn the pile every 14 days or so. The more you turn the pile the faster you will have finished compost! Step Six: Using Your Compost Congratulations! Your compost is ready to use! It can take anywhere from 14 days to 12 months to produce your finished compost. The time it takes can vary widely depending on the materials and methods used. Check out the making a compost pile section below for tips on how to make high quality compost in record time. The point at which the compost is ready varies based on how the compost will be used. In general, though, compost is ready when dark and crumbly and mostly broken down with a pleasant, earthy, soil-like smell to it. For most uses it is acceptable to have some recognizable pieces of leaves or straw remaining. Compost can be used for: House Plants Soil amendment and fertilizer Flower and Vegetable Beds New planting areas Established planting areas Lawn top dressing Compost Tea Around trees
You can now pat yourself on the back. You have put back into the soil. Your house plants, flowers, vegetables and trees will thank you by growing stronger and healthier than ever. Making a Compost Pile Before we get down to details, a few words about the amount of brown (carbon) material, versus green (nitrogen) material to put into your compost bin. Adding too much brown material will result in a pile that takes a long time to break down whereas too much green material will result in a slimy, smelly pile that doesn't heat up effectively. In order for our pile to break down quickly and efficiently we need to provide just the right balance of brown and green materials. The microorganisms in our compost bins need both carbon and nitrogen to thrive; carbon for energy and nitrogen for protein synthesis. For every one unit of nitrogen used by the bacteria they also consume about 30 units of carbon. And so in order to keep the bacteria working efficiently we need to create an environment for them that is approximately 30 parts carbon to 1 part nitrogen. Unfortunately, most composting materials don't have a carbon to nitrogen (C:N) ratio of 30:1. However, if we know the approximate C:N ratio of the materials we use in our compost, we can combine them so that the total mixture will be as near as possible to 30:1. This may sound a bit complicated but it really isn't. Here's an example: We want to have a ratio of 30:1 in our compost bin but we only have access to the following ingredients: dry autumn leaves (C:N of about 50:1) kitchen scraps (vegetable & fruit peelings, coffee grounds etc: about 12:1) grass clippings (about 20-30:1) sawdust (fresh: 500:1, rotted 200:1) Using different combinations of materials we will try to get close to the magic 30:1 ratio. If we use 1 part dry leaves to 1 part kitchen scraps we would have the following: leaves 50/1 + kitchen scraps 12/1 = 62/2 = 31/1 or 31:1
If we use 1 part leaves, 1 part kitchen scraps and 1 part grass clippings we would have: 50/1 + 12/1 + 20/1 =82/3 = 27:1. Not too bad. In this example we can add some extra leaves or a handful or two of sawdust to bump up the ratio nearer to 30:1 Getting the mix of ingredients right is obviously not an exact science but a matter of trial and error. It's something that gets easier after a few tries. Now for the part about the Giant Layer Cake... Layering the compost pile Start with a 4 inch layer of brush, twigs, hay or straw at the bottom of the compost bin. If you don't have these materials, dry leaves will do. This first layer should be as coarse as possible to allow air to be drawn up into the pile from the bottom of the bin. Then add a 4 inch layer of brown material, then a thin covering of finished compost or good garden soil. That's one layer. The addition of compost or soil is to provide the necessary bacteria to get the compost to start breaking down. If we don't add this layer the compost will still work, the addition just helps to speed things along. Then add a 4 inch layer of green material topped with a thin layer of an activator. Activators are a source of both nitrogen and protein, ingredients that assist the organisms to break down the material. There are a number of good activators. Alfalfa meal works amazingly well. You can also use fresh manure, bone meal, blood meal, cottonseed meal, or even high-protein dry dog food (yes, that's right, dog food!). Continue adding materials in alternating layers of greens and browns until the compost bin is full. Moisture Moisten each layer by misting it lightly with a garden hose. The key is to moisten the pile without making it too wet and soggy. Many people recommend adding moisture until the material is as moist as a wrung out sponge. This is far too wet. If you can squeeze water out of it, it's far too wet. Adding some dry brown materials such as chopped leaves or hay will help if this happens.
If you live in a very arid climate, make an indentation in the top of the pile to collect rainwater and help keep the pile moist. Those living in rainy areas can cover the top of the pile with a tarpaulin or cover to keep it from becoming waterlogged. Turning the Compost Pile If the pile has been made correctly the internal temperature should reach about 140 F within 7-10 days. Ideally, the pile should heat up to 160 F so that any weed seeds and pathogens will be destroyed. A compost thermometer is a helpful tool to use at this stage. Since the bacteria need air to survive they will start to die off after a week or so as they start to use up the available air in the pile. This drop in the amount of bacteria will result in the compost pile cooling off a bit from its peak temperature. When this happens it's time to turn the pile to get more air into it. When turning your compost pile, move the drier material from the outer edges into the center of the pile and break up any clumps of leaves or grass clippings to ensure that you get as much air into the pile as you can. Moisten any of the materials as you go, if they seem too dry. From this point on you should turn the pile every 14 days or so, or when you see the temperature fall from the next peak in temperature of about 43-48 C (110-120 F). In general, the more you turn the pile the faster you will have finished compost. If you're using a plastic compost bin, an aerator tool will make the job of turning much easier. A garden fork is often the best tool for turning compost in an open style bin. What should I do if I don't have enough materials to fill the compost bin all at once? When you can get your hands on some brown materials such as autumn leaves, save them in bags or a separate bin nearby your compost bin. When you have added enough green material to your compost bin to make a four inch layer, cover it with a 4 inch layer of the saved brown material. Then you can start building another green layer.